1. Field of the Invention
The present invention relates to a snow vehicle and, more particularly, to a snow vehicle equipped with an engine including a crankshaft and a balancer shaft.
2. Description of the Related Art
Heretofore, engines including a crankshaft and a balancer shaft have been known. Such an engine is disclosed, for example, in U.S. Pat. No. 5,829,401.
This disclosed engine is an automotive engine including a crankshaft and a balancer shaft disposed below the crankshaft that is on an extension line of a cylinder shaft.
In the automotive engine disclosed in the above-mentioned patent, it is difficult to reduce the dimension of the engine in the vertical direction because the balancer shaft is positioned below the crankshaft on an extension line of the cylinder shaft. The snow vehicle has the problem that limitations are imposed on the vertical dimension, making it difficult to equip an automotive engine as described above.
Accordingly, a snow vehicle equipped with an engine having a restricted vertical dimension has been heretofore proposed as in U.S. Patent Publication No. 2004/0251072.
In the engine of the snow vehicle proposed in U.S. 2004-251072, a front balancer shaft is disposed ahead of and above a crankshaft, while a rear balancer shaft is located under and to the rear of the crankshaft. The starter motor is positioned to the rear and above the crank shaft. In the snow vehicle disclosed above, the engine is tilted obliquely rearwardly. The front balancer shaft is disposed ahead of and above the crankshaft, whereas the rear balancer shaft is positioned to the rear and below the crankshaft. Consequently, the front and rear balancer shafts can be prevented from being disposed below the crankshaft. As a result, increases in the vertical dimension of the engine can be reduced.
However, in the structure proposed in U.S. 2004-251072, the rear balancer shaft is mounted below the starter motor. This creates an undesirable situation where a heavy starter motor cannot be easily positioned in a lower position. This makes it difficult to place the center of gravity of the engine in a lower position. As a result, there is the problem that the center of gravity of the snow vehicle is not easily placed in a lower position. This results in a problem that the stability of the snow vehicle during operation cannot be easily improved.